/**
 * Copyright (C) 2016 Juno Inc., All Rights Reserved.
 */
package com.jyl.util.randomCode;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;
import org.springframework.util.StringUtils;

/**
 *
 * 验证码工具类
 * @author Long, E-mail:jyl0401@163.com
 * @date 2016年7月12日 下午9:21:54
 */
public class RandomCodeUtils {
	
	private static Logger logger = Logger.getLogger(RandomCodeUtils.class);  
    
    private static final String RANDOM_CODE_KEY = "validateCode";
      
    private static final int CODE_NUM = 4; //验证码字符个数  
      
    // 设置图形验证码中字符串的字体和大小    
    private static Font myFont = new Font("Arial", Font.BOLD, 16);     
    
    //随机字符数组  
    private static char[] charSequence = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();  
          
    private static Random random = new Random();  
      
      
    /** 
     * 生成随机验证码 
     * @param request 
     * @param response 
     */  
    public static void createRandomCode(HttpServletRequest request, HttpServletResponse response){  
        // 阻止生成的页面内容被缓存，保证每次重新生成随机验证码    
        response.setHeader("Pragma", "No-cache");    
        response.setHeader("Cache-Control", "no-cache");    
        response.setDateHeader("Expires", 0);    
        response.setContentType("image/jpeg");    
        // 指定图形验证码图片的大小    
        int width = 80, height = 25;    
        // 生成一张新图片    
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);    
        // 在图片中绘制内容    
        Graphics g = image.getGraphics();     
        g.setColor(getRandomColor(200, 250));    
        g.fillRect(1, 1, width - 1, height - 1);    
        g.setColor(new Color(102, 102, 102));    
        g.drawRect(0, 0, width - 1, height - 1);    
        g.setFont(myFont);    
        // 随机生成线条，让图片看起来更加杂乱    
        g.setColor(getRandomColor(160, 200));    
        for (int i = 0; i < 155; i++) {    
            int x = random.nextInt(width - 1);// 起点的x坐标    
            int y = random.nextInt(height - 1);// 起点的y坐标    
            int x1 = random.nextInt(6) + 1;// x轴偏移量    
            int y1 = random.nextInt(12) + 1;// y轴偏移量    
            g.drawLine(x, y, x + x1, y + y1);    
        }    
        // 随机生成线条，让图片看起来更加杂乱    
        for (int i = 0; i < 70; i++) {    
            int x = random.nextInt(width - 1);    
            int y = random.nextInt(height - 1);    
            int x1 = random.nextInt(12) + 1;    
            int y1 = random.nextInt(6) + 1;    
            g.drawLine(x, y, x - x1, y - y1);    
        }    
    
        // 该变量用来保存系统生成的随机字符串    
        StringBuilder sRand = new StringBuilder(CODE_NUM);    
        for (int i = 0; i < CODE_NUM; i++) {    
            // 取得一个随机字符    
            String tmp = getRandomChar();    
            sRand.append(tmp);  
            // 将系统生成的随机字符添加到图形验证码图片上    
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));    
            g.drawString(tmp, 15 * i + 10, 20);    
        }    
    
        // 取得用户Session    
        HttpSession session = request.getSession(true);    
        // 将系统生成的图形验证码添加    
        session.setAttribute(RANDOM_CODE_KEY, sRand.toString());    
        g.dispose();    
        // 输出图形验证码图片    
        try {  
            ImageIO.write(image, "JPEG", response.getOutputStream());  
        } catch (IOException e) {  
            e.printStackTrace();  
        }    
    
    }  
      
    /** 
     * 检查用户输入的验证码是否正确 
     * @param request 
     * @param inputCode 
     * @return true: 正确, false:不正确 
     */  
    public static boolean checkRandomCode(HttpServletRequest request, String inputCode){  
        HttpSession session = request.getSession(false);  
        if(session != null && StringUtils.hasLength(inputCode)){  
            String code = (String) session.getAttribute(RANDOM_CODE_KEY);  
            logger.info("inputCode:"+inputCode.trim()+",code:"+code);  
            return inputCode.trim().equalsIgnoreCase(code);  
        }  
        return false;  
    }  
      
    /** 
     * 移除验证码 
     * @param request 
     * @param inputCode 
     */  
    public static void removeRandomCode(HttpServletRequest request){  
        HttpSession session = request.getSession(false);  
        if(session != null){  
           session.removeAttribute(RANDOM_CODE_KEY);  
        }  
    }  
      
    // 生成随机颜色    
    private static Color getRandomColor(int fc, int bc) {    
        Random random = new Random();    
        if (fc > 255)    
            fc = 255;    
        if (bc > 255)    
            bc = 255;    
        int r = fc + random.nextInt(bc - fc);    
        int g = fc + random.nextInt(bc - fc);    
        int b = fc + random.nextInt(bc - fc);    
        return new Color(r, g, b);    
    }    
      
    // 随机生成一个字符    
    private static String getRandomChar() {    
        int index = random.nextInt(charSequence.length);  
        return String.valueOf(charSequence[index]);  
    }  

}
